Require user login to submit form

Question

How can I require that a user be logged in, in order to submit an input?

I found this piece of code, not sure how I can modify it to suit my needs:

add_action('login_head','ref_access');

function ref_access() {

    global $error;

    if( !empty($_GET['ref']) && 'access' == $_GET['ref'] )
        $error  = 'Restricted area, please login to continue.';
}

This input will be posted to a MySQL database.

This is the input code as it stands in my plugin:

<input type="text" maxlength="4" name="' . $quanid . '" value="" class="input" />

As of right now, anyone can submit this, regardless of login status.

Answer 1

You can use Wordpress's built in function for that: is_user_logged_in() .

Example:

function ref_access() {

    global $error;

    if (is_user_logged_in()) {
        // process form here.

    }else {
         $error = "Hey, get out of here";
         return ; 
    }
}